1. Field of the Invention
The invention relates to a slot machine. More particularly, it relates to a slot machine which provides a player with a free game as a reward if a bonus trigger symbol or a combination including a bonus trigger symbol appears along a pay line, when the symbols in every column come to rest.
2. Related Art
Slot machines having a so-called free game have become popular recently. These slot machines provide the free game in order to increase the excitement of a player when a bonus trigger symbol or a combination of symbols including a bonus trigger symbol appears.
Patent Document No. 1 discloses a typical example of the slot machine described above.
The slot machine disclosed in Patent Document No. 1 performs a game prior to a free game so as to determine a payout given for the free game. The slot machine displays the determined payout.    Patent Document No. 1: Japanese Unexamined Patent Application Publication No. 2004-57221
However, the slot machine disclosed in Patent Document No. 1 internally determines the payout described above by an electronic lottery, such as one with random numbers. This means that the slot machine cannot give a player a chance to participate in the outcome of the lottery. Accordingly, the player may have a distrust of the payout given by the free game.